Abstract: Metamodels evolve over time, as well as other
artifacts. In most cases, this evolution is performed
manually by stepwise adaptation. In most cases, metamodels
are described using the MOF language. Often OCL
constraints are added to metamodels in order to ensure
consistency of their instances (models). However, during
metamodel evolution these constraints are omitted or
manually rewritten, which is time consuming and error
prone. We propose a tool to help the designer to make a
decision on the constraints attached to a metamodel during
its evolution. Thus, the tool highlights the constraints
that should disappear after evolution and makes
suggestions for those which need adaptation to remain
consistent. For the latter case, we formally describe how
the OCL constraints have to be transformed to preserve
their syntactical correctness. Our adaptation rules are
defined using QVT which is the OMG standard language for
specifying model-to-model transformations.